Ion beams have been found to be useful in a variety of different technologies, such as in highly controlled ion implantation, surface etching or milling, sputtering, mass spectrographs, submicron lithography, microelectronic circuit fabrication, electric propulsion devices, and microthrusters for station keeping or attitude control of satellites, to name a few.
Currently available means and methods of generating ion beams are subject, however, to a number of drawbacks which significantly limit their performance, efficiency, utility and scope of use. Such limiting drawbacks of prior art ion sources or generators include the following:
(1) The obtainable "brightness" of the generated ion beam currents (i.e., ion current per unit area per unit solid angle) of prior art ion sources is limited.
(2) The prior art apparatuses are relatively "delicate," frequently resulting in life-limiting operation. For example, in the prior art electron-bombardment type sources, filament cathodes or oxide cathodes, and cathode heaters or arc voltage supplies are required.
(3) The prior art ion sources are relatively complex, cumbersome, difficult and expensive to manufacture and operate.